SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20d1d438bf10dafccdcbf3adb5573123fb8a4eab82ae951d1910dfc709f8660e' 
  AND token = '76/F/QrZ1l8gCRgBJhPqXvJezG0a7Bgj3qtz53rAHT8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}